This invention relates to brake components, and more specifically, the invention relates to an apparatus and method of cooling brake components.
Modem vehicles are required to stop in shorter distances than previously necessary to improve vehicle performance and handling. Braking components, such as brake rotors and drums, calipers, and brake pads, have experienced higher operating temperatures as the demand for shorter stopping distances has increased. As the temperature of the brake component exceeds its thermal capacity, the performance of the component may be compromised and the stopping distance increased. For example, the rate of wear may increase or the brakes may xe2x80x9cfadexe2x80x9d and become virtually inoperative due to the higher temperatures.
The problem of higher temperatures is exacerbated by the tighter packaging of modem vehicles. The size of brake components has been reduced to decrease weight and cost, which has reduced the thermal capacity of the affected brake component. Brake components, such as rotors, have utilized ribs or vents to increase the surface area to increase heat dissipation and cooling of the rotor. However, tighter packaging has adversely affected airflow through the brake components, which has reduced the cooling effects of convection around the brake components. As a result, the ribs on a rotor are less effective at dissipating heat. Therefore, what is needed is an apparatus and method for effectively cooling smaller modem brake components in the tighter spaces found in modem vehicles.
The present invention provides a cooling device for a brake component. The brake component includes a structural element that has an interior cavity. A cooling material is disposed within the cavity. The material has a phase change temperature at a particular pressure and volume. The material absorbs the heat generated by the structural element by changing from a first state to a second state at the phase change temperature to maintain the brake component or structural element below the maximum operating temperature. The phase change temperature may be defined by a melting point of the material in which the first state is solid and the second state is liquid, or by an evaporation point of the material in which the first state is liquid and the second state is gas.
Accordingly, the above invention provides an apparatus and method for effectively cooling smaller modern brake components in the tighter spaces found in modem vehicles